that's nice to know. I'm guessing it was a P4 T bin> P4 U2 bin upgrade, which is pretty easy to do (just unsolder the existing LED and solder the new one in). I have an idea for a simple way to use the XM-L in the Minewt housing, but I have to wait for someone in my group to need it doing first. Rather than reuse the existing board (or bits of it), you just have to wire 2 1kO (or 1.2kO, I'd have to check) resistors between the + pad, yellow wire and - pad of the LED. That would get ~350-400lm for not much effort.